ESL systems typically include a plurality of ESLs for each merchandise item in a store. ESLs display the price of corresponding merchandise items on store shelves and are typically attached to a rail along the leading edge of the shelves. A store may contain thousands of ESLs to display the prices of the merchandise items. The ESLs are coupled to a central server where information about the ESLs is typically maintained in an ESL data file which contains ESL identification information and ESL merchandise item information. The central server sends messages, including register update messages, to the ESLs.
While prior ESL systems provide many of the capabilities required by retailers, these systems may suffer from various disadvantages. For example, when an update of an ESL's registers was required, a prior ESL system would typically transmit an update all of the ESL's registers, even if only a portion of the registers needed to have new data written to them. Such a full data update of all of the ESL's registers can take a significant amount of time to transmit and process, impacting overall system performance when a large number of ESLs are being updated. Therefore, it would be desirable to provide an ESL system and method that provides for a delta update technique which only updates registers which are scheduled to store new or updated information.